A six-year maritime dispute between Chile and Peru was settled by the International Court of Justice in The Hague, ruling largely in favor of Peru.
The dispute concerns the delimitation of the boundary between the maritime zones of the two States in the Pacific Ocean including the recognition of a large Peruvian maritime zone (28'356 km²) lying within 200 nautical miles of Peru's coast, and thus appertaining to Peru, but which Chile considers to be part of the high seas.
In 2008, Peru, under President Alan García, took Chile to the World Court.

The dispute was a legacy of the War of the Pacific, which lasted from 1879 to 1883. Chile won, conquering Peruvian territory and depriving Bolivia of a coastline. A treaty between Peru and Chile in 1929 granted Chile control of Arica, and the countries later fixed a land boundary. The maritime boundary, however, was never fully defined.

Peru's request:
"The Republic of Peru requests the Court to adjudge and declare that: one, the delimitation between the respective maritime zones between the Republic of Peru and the Republic of Chile, is a line starting at 'Point Concordia', defined as the intersection with the low-water mark of a 10-kilometre radius arc, having as its centre the first bridge over the River Lluta of the Arica-La Paz railway and equidistant from the baselines of both Parties, up to a point situated at a distance of 200 nautical miles from those baselines, and, two, beyond the point where the common maritime border ends, Peru is entitled to exercise exclusive sovereign rights over a maritime area lying out to a distance of 200 nautical miles from its baselines."

Chile's request:
"Chile respectfully requests the Court to dismiss Peru's claims in their entirety and to adjudge and declare that, one, the respective maritime zone entitlements of Chile and Peru have been fully delimited by agreement; two those maritime zone entitlements are delimited by a boundary following the parallel of latitude passing through the most seaward boundary marker of the land boundary between Chile and Peru, known as Hito No. 1, having a latitude of 18° 21' 00" S under WGS84 Datum; and three, Peru has no entitlement to any maritime zone extending to the south of that parallel."

Chile argued that the border had been clearly established by fishing treaties signed by Chile, Peru and Ecuador in 1952 and 1954; by subsequent agreements; and by customary practice and the unilateral actions of Peru.
The court agreed to those arguments, but also recognized that those treaties had not expressly defined a general maritime boundary. Therefore the court settled on a compromise, akknowledging the status quo for the first 80 miles from the coast along a line of latitude and beyond that the customary delimitation constructed on the equidistant from the baselines of both Parties, up to the point situated at a distance of 200 nautical miles from those baselines.